1. Field of the Invention
This invention relates to an apparatus for easily interconnecting two tubes to form a T-shaped tube unit.
2. Description of the Related Art
Referring to FIG. 1, a conventional coupling apparatus includes a nut (A), which is welded into an end portion (B1) of a first circular tube (B), and a bolt (C) extending through the hole of a second circular tube (D) to engage with the threaded hole (A1) of the nut (A). To avoid the welding process, an improved coupling apparatus has been developed. Referring to FIGS. 2 and 3, the improved coupling apparatus includes a nut (D') and two resilient securing members (E) secured to two ends of the nut (D'). As illustrated, the resilient securing members (E) have a convex side surface, a concave side surface, and a plurality of radial projections (E1) so as to be press fitted in an end portion (F1) of a first circular tube (F). A bolt (G) extends through the hole of a second circular tube (H) to engage with the nut (D'). Because particular tools or machines are needed to force the assembly of the nut (D') and the resilient securing members (E) into the first circular tube (F), it is time-consuming to couple the first circular tube (F) with the second circular tube (H). The tools and machines may scratch the paint or the like on the tubes (F, H). Furthermore, because the axes of the nut (D') and the resilient securing members (E) may be on different lines, the axis of the nut (D') may be deflected from the axis of the first tube (F), changing the angle formed between the tubes (F, H).